Electric switch control station



y 6, 1952 c. A. SCHAEFER ELECTRIC SWITCH CONTROL STATION 2 SHEETS-SHEET 1 Filed Sept. 22, 1949 IN V EN TOR.

f M 4% g 5 M V. as

May 6, 1952 c. A. SCHAEFER ELECTRIC SWITCH CONTROL STATION Filed Sept. 22, 1949 2 SHEETS-SHEET 2 IN V EN TOR. 64/! /7 56%46/6/7 Patented May 6, 1952 ELECTRIC SWITCH CONTROL STATION Carl vA. Schaefer, Milwaukee, Wis.-, assignor to Square D Company, Detrit, Mich., a corporation of Michigan Application-September 22, 1949, Serial No. 117,188

12 Claims.

This invention relates to electrical. control stations. More specifically, this invention relates to control stations for electrical systems comprising a plurality of switching mechanisms actuated by an operating lever acting through camming means which determine the switch operation.

In many industrial -applications,- and particularly in textile manufacturing, it is-desirable to use magnetic starters with a control mechanism which will be both sturdy-and compact, and

which will, when placedin operative position in an electric motor. circuit, provide. for start ing and stopping. of the motor, inching or doiiing operationwith only a small movement of an operating-handle, and which will provide connections for both low. voltage and overload control of the electric motor, the requirement that the operating handle be moved to off position following a condition of overload. or low voltagebefore the motor can be reenergized. It is therefore an object'of the present invention to provide a control mechanism which provides all of the above desired featuresand which'fufi ther provides for great flexibility'of'operation,

by permitting reverse operation 'of' the device by a simple switchingof terminal. connections.

Anotherobject of the invention is 1 the pro-' vision of an electrical control "station providing for the sequential operationof a pairof switches by a pair of operating levers havingcam surfaces acted upon by the operator for the station.

Another object of the invention is the provision of an electrical contrclstati'onfin a-ccord- I ance with the preceding object-"in which one of the levers is provided with-cam surface elements at opposite sides-of the camsurfaceelement on vice of the present invention in which a portion.

of the cover is broken away'to-sh'owthe internal structure.

Figure 2 is a sectional view along the-.line.

II-II of Figure 1.

Figure 31s a detailviewalong the line-IIIIII.

of Figure 1.

Figure 4 is a sectional view-similar to Figures with the parts in another operating position.

Figure 5 is a sectional view similar toFigure 3 with the parts in a third operating positions Figure 6 is a detail view 'of the double stepped camming member employed in the device.

Figure 7 is a detail. view of the single stepped camming member. employed inzthezdevice;

Figure S is a detail view'of theswitchin'gmech;

anismr. employed in the present invention as viewedalongithe-line'VIII-VIII of Figure 1,,

Figure 9- is-a schematicviewof the circuit employed in-cooperationwith the deviceof th present invention;

The device of the present invention comprises metal boxlike structure I having mounting holes'Zand-provided with a metal cover 3'secured totherbox I by suitable securing screws 4.

Extending through an aperture in a raised portion 5 on the bottomof the box I and through a suitable recess in the. right-side of the box i, as viewed in Figure l, is an operating shaft 6, on the exterior end of which a slotted operating handle I :isclamped by means ofthe screw meme her-8. Disposed between the operating handle 1 and theouter wall of the box I, and also mounted uponthe operating. shaft 6, is a rotational limiting. disc 9-.whic'hl cooperates with a stud H which projectsirom theouter wall of the box I to permit'rotation of the operating handle I through an .arc of "approximately, degrees, the operaticinallarc. as shown, having as limits the vertical position shown in Figure 1 and a position approximately 100 degrees away from that vertical position. in a forward direction, perpendic ular to the plane. of Figure 1.

Upon'the'interior end of the operating shaft 'fi'thereis. secured 'a' circular operating disc I2 which is fastened 'to'the operating shaft '6 by a screw I3'prevent'ing any relative movement be tweenftheshaft Gandthe disc I2. An operating studjl l'projects fromthe disc I2, the stud [4 serving to rotatably mounta roller member I5 of a suitable, hard material, the rollermember being loosely mounted upon the stud I4 and capable of rotational movement thereon.

The roller member I5a'buts against two camming-membersI5-and ll', the member ifi'being shown-'inF-igure- 6 and having two camming steps ifl and I9.- In Figure 7, the member I1 is-shown; it has. but one camming step 2l which, however, is abouttwice as large as either step I8 or It; A-pairoi posts 22 and 23 are provided projecting from. th'e bottom of theboX I with th'e member ESh'aVing-a stud 24 rotatably mounted with-in 'a-suitable aperture in the post 22, while'th'e: member ITh'asa similar'stud 25 rotatably-mounted within a-suitable aperture in the post- 233 The two camming members Iii'and I'I are'therefore mounted in juxtaposed position, the member ittbeing closest to theo'bserver in the. views -t'shcwn'rini'Figures 2-5.

A-i-prrojectionifi extends from, and perpendicularzto .the zplaneaof; the cam member I5 and carrieaascrewil: having operatinghead 29, the

screwland: projection 26 being: biased away fromrthfe-tbottom" of the base I by'aspring 28. For the: purpose of. explaining the operation of theddevicexthis" end of the member I6 will be termed .lthe operative end thereof.

In a like manner, the cam member I! carries a perpendicular projection 31 which extends therefrom, and carries a screw 32 with operating head 34 and with the combination biased away from the bottom of the base I by a spring 33. Employing terminology analagous to that used in describing member 16, this end of the member I! will be termed the operative end.

Projecting from the bottom of the box I are four posts 35, two of which, as may be seen in Figure 8, support a switching device 33, the other pair serving to support a switching device 31, mounting screws 33 being used to maintain the switching devices in position upon their respective posts. The switching devices 36 and 31 are identical in construction, the device 35, as employed in the specific embodiment herein described, being illustrated in Figure 8. The device 35 comprises an exterior boxlike member, which is broken away in Figure 8 to facilitate explanation, upon which are disposed a pair of exterior terminals 62 and 63 (indicated by the letter A in Figure 9) which are electrically connected to a pair of stationary contacts 42 and 43. These contacts cooperate with movable contacts 44 and 45 respectively, the latter pair of contacts being mounted on a bridging conducting member 43 which is normally maintained in the position shown in Figure 8 by a spring 41 which biases an operating button 48 outwardly. Leaf springs 49 are provided to effect snap action of the movable contacts, upon operation of the button 48, from the position shown in Figure 8 to that position in which they contact a second pair of stationary contacts 5|, 52 electrically connected to a pair of external terminals also mounted upon the boxlike enclosure and shown diagrammatically as B in Figure 9, and numbered 69 and I I.

The switching device 31 is shown in Figure 9 to also have two pair of terminals C and D, the

terminals C, shown as 66 and 68, being electrically connected to the pair of stationary contacts which are bridged by the movable contacts when the operating button of device 31 is in its extended, outward position. Conversely, the D terminals l2 and 13 are electrically connected to the pair of stationary contacts which are bridged by the movable contacts when the operating button is depressed.

Both of the switching devices 36 and 31 employed in this device are of the type in which snap action occurs at one position of the operating button as the button is moved in, and at another, different position as the operating button moves out. For example, in one form of switch, snap action occurs during the inward movement at a position at which the operating button is depressed about 0.05 inch from its normal extended position; while snap action occurs during the outward movement when the operating button is only about 0.015 inch from its normal position. This particular switch was the subject of an application of Hermon L. Van- Valkenburg for Electric Switch, Serial No. 866,289, filed May 1, 1946, this application having been abandoned. It should be noted, however, that the device of the present invention is in no way limited to the use of this particular switch, which of itself forms no part of the present invention, as devices in which the snap action occurs to operate the switch at one position as the actuator is moved in, and at another position as the actuator is moved out, are well known. For example, one such switch of this general type is shown and described in Patent No. 2,476,056,

,- contact M and terminal 62.

4 issued July 12, 1949, the patentee being Wilbert A. Martin (See column 3, lines 42-56).

In Figure 9 the device of the present invention is shown in operative position in an electric cir cuit which comprises an electric motor 53 which is connected to supply lines 54, 55 and 55 through conventional circuit protecting equipment and normally open contacts 51 after a coil 58, con trolling the closure of the contacts 5'1, has been energized through the device of the present inmembers of the device of the present invention assume the position shown in Figure 3, with the roller [5 abutting against the camming members it and H as shown. In this position, the operative end of member I6 is depressed against the bias of spring 28 by the roller [5 while the surface of the cam member I! is such that the operative end of member I! is in raised position, the spring 33 being fully extended with the head 34 abutting against and fully depressing the operating button of switching device 31. In this position, as may be seen in Figure 9, there is no closed circuit through the coil 58. As the handle 2 is moved about 47 degrees away from the off position in a clockwise direction, as viewed in Figure l, the internal members assume the position shown in Figure 4 in which the roller I5 has passed the cam step [9 of member 16, with only a small movement of its operative end, and in which member l5 has just touched the cam step 2| of camming member l1. It will be seen that the operative end of the member l6 has been permitted to raise slightly under the bias oi spring 23, with the screw head 29 slightly depressing the operating button 48 of switching member 35, this slight depression being insufficient, howver, to effect a snap action of the device. It will further be seen that member I5 has not forced the operative end of member I! downward against the bias of spring 33, the operating button of switching device 31 not having been permitted to move.

As the operating handle is moved only about six degrees further in the direction to cause clockwise movement of the roller I5 from the position shown in Figure 4, the roller rides up cam step 2| of camming member [7, forcing the operative end thereof downward, compressing spring 33 and permitting the operating button of switching device 31 to move outward under the influence of the internal spring of that device which corresponds to the spring 41 of device A snap movement of the bridging contact member of device 31 is therefore effected, the bridging member leaving the D contacts shown in Figure 9 and electrically connecting the C contacts 66 and 68 together.

From an inspection of the diagrammatical circuit of Figure 9, it will be seen that current will now pass from supply line 54 through coil .58, conductor 6|, to terminal 63, through the movable contacts and bridgingmember 46 toterminal I 62, through conductors to terminal; 68, through the movable contacts and bridging member of -the-device'31' to terminal J 66, and: thenceto the supply line 56 viatheconductor The Y energization ofcoil 58" will cause the 64.- contacts 51 (and the contact 14) to close, there-v by: connecting the-motor 53- to all three supply 1ines 54, 55 and 56; Underthisscondition..the.

motorwill run, and itshouldb'e: notedthat the motor may. be Pinched bymoving; theoperating handle only about: six1;degrees,.-. the; motor... rune nin'g: when the. roller; 5chas :reached .the left edge of thecam steps, 21, as .viewedtin Figure 4,, the. motor: stopping when; the; operating handle; is moved so. as :to. causeztheroller I5 to :return to the right edge 1 of step; face: 2,! the: position illustrated 1 in Figure: 4;

If normal runningv ofuthegmotor, as-:distinguished' from inching? is desired, .the operatingv handle '1 may bemovediromthe position of Figure 4 in" a direction 1 which will;cause-the the spring 28 is permitted to further expand forcing the screw head 29 todepress operating lever 48 of switchingdevice 3-6 to such a degree that the device 36 is operated, The movable contacts 44 and 45 and the conducting bridging member 45 of device 36+are thereby moved from theposition shown. in Figure 8into aposition in which the movable contacts engagethe stationary contacts 5| and. 52. Referring to Figure 9, the terminals A are disconnected, ,and the terminals B are connected together.. In this position of the device, themotor will continue to run, inasmuch as the holding contact .14. is closed, maintaining, coil 58 energized.

It should be noted that in this position, should an overload occur which issuflicient to open circuit protective elements ,associatediwith. the circuit, or should a condition .of.low.voltage be experienced, the coil 58 willimmediatelybecome deenergized, causing thecontacts. 5T and 145 to open and the motor 53 to,stop.,, After suchan occurrence, themotor may not berestarte'd until the. operating, handle has I been. moved through an arcsuch, that. the roller 1 5 has passed cam step 2| of camming-. member I11 and both cam steps IS and, ltqofcamming member it,

since it is not until'istep, I9Tis passed thatjthe switch will be operated;

With the above ,operation,it, will .be seen that after opening of the motor controlling switch by deenergiz'ation of the 001158 forany reason; that it is impossible for the motor to .be reconnected to the line by. a. reenergization of Jthecircuit until the handle ,li'has been vmoved to,its ,full off position. This presents anzinvoluntary operation of the mechanism controlled'jby the. motor after a failure has occurred andis particularly desirable in cases where such involuntary operation might effect damage if occurring in the middle of an operating cycle. With the device of this invention, after such-failure, a

voluntary act of an operator must-be performed before a motor will be reenergized;

It will readily appear that the device of the present invention may be connected in a, variety of positions .,and that the device .therefo'reimparts a very large measure'oi' flexibility to any system with which it is4associated ample, operating conditions may require that the operating handle be on the: left side; insteadcf on the right side as in-the specific embodiment: described. This requirement may be'met: by; first, inverting the device; then,

by removing the connections to thedevice shown-- in Figure 9; and reconnecting: conductor 61- between terminalsi'l and 13, connecting con-- ductor 64 to. terminal '12, conductor 59 to terminal H, and conductor 6| to terminalBS.

ating handle is in its most raised position.

Similarly; the device may be easilyconverted to provide either-left or right hand operation in which theoff position occurs-when the" operating handle is in its most' lowered position bymerely reversing the position- 0f the =operating handle. It will be seen, therefore, that the deviceof the present invention is highly-adaptable and may bereadily adjusted to'meet'the requirements of all operating conditions.=

While certain-preferred embodiments of the inventionhave been specificallydisclosed, it is understood that the invention is not limited thereto, as many variations will be readily-apparent'to those skilled in the-art and thednvention is to be given its broadest possible interpretation within the: terms of the following claims:

What is claimed is:

1. In an electrical control, station, afirstswitching mechanism, means foroperating said first mechanism including a lever having one camming. surface," a second switching mechanism,

means for operating said second mechanism includinga second lever having at least two spaced camming surfaces, means for mounting said levers in a contiguous relationship with said 'one camming surface between said two camming sur-- faces, operating means, and'means for-'efiecting movement of said operating meansacross all said camming surfaces.

2. In. an electrical control a station, a first lever having a single cam stop, a second lever having at least 'a pairof spaced cam stepspoper ating means, means for operatively relating said operating means :to the cammed surfaces of said said operating means upon-both of said-pair-oi cam steps, and a pairof switching mechanisms operated by said levers.

3. In an electrical control station,- a-first lever having a single cam step, a second lever'having at least a pair of spacedcam steps; operating means, means for operatively relating said operating means to the cammed surfaces of said levers, means mounting said 'levers'j'sothat tsaid operating means engages one of saidpair of cam steps and said singlecam step before engaging theother of said pair as said operating means is moved in one direction along the length of said levers, said operating means upon engaging said single cam step effecting a movement of said first leversubstantially equal to twice the movement imparted to said second lever by the operation of said operating means upon either of said pair For-- ex-:

The device willoperate as described above with the off positionagain occurring when the oper 7 of cam steps, and a pair of switching mechanisms operated by said levers.

4. In an electrical control station, a first lever having at least two spaced camming steps, a second lever having at least one cam step, biasing means for said levers, means pivotally mounting said levers, means including an operator operating upon both of said levers, means for moving said operator against the cammed steps of said levers to overcome said biasing means, the second of said levers being moved against its biasing means by the operation of said operator upon said one cam step a distance substantially equivalent to the distance the first of said levers is moved against its biasing means by the operation of said operator upon both of said cam steps, and a pair of switching mechanisms operated in response to the movement of said levers.

5. In an electrical control station, a first lever having at least two spaced camming steps, a second lever having at least one cam step, biasing means for said levers, means pivotally mounting said levers, means including an operator operating upon both of said levers, means for moving said operator against the cammed steps of said levers to overcome said biasing means, the second of said levers being moved against its biasing means by the operation of said operator upon said one cam step a distance substantially equivalent to the distance the first of said levers is moved against its biasing means by the operation of said operator upon both of said cam steps, and a pair of switching mechanisms operated in response to the movement of said levers, and means for effecting operation of said switching mechanisms at predetermined lever positions.

6. In an electrical control station, a first lever having an arcuate surface with one cam step, a second lever having an arcuate surface with at least a pair of spaced cam steps, biasing means for said levers, means rotatably mounting said levers in a contiguous relationship with said one cam step between said pair of cam steps, an operator, means including an operating handle for pressing said operator against selected portions of said arcuate surfaces, a pair of switching mechanisms operated by said levers, and means for effecting operation of said switching mechanisms at predetermined lever positions.

7. In an electrical control station, a pair of switches, rectilinear operating means effecting the switching operation, said switching operation occurring at one position of the rectilinear operating means as said means is moved inward and at a different position of said means as said means is moved outward, a first lever with one cam step for actuating one of said operating means, a second lever having at least a pair of cam steps for operating the other of said oper-- ating means, means rotatably mounting said levers in side-by-side relationship so that said one cam step is between said pair of cam steps, an operator, and means including an operating handle for selectively positioning said operator along said levers.

8. In an electrical control station, a pair of switches, rectilinear operating means effecting the switching operation, said switching operation occurring at one position of the rectilinear operating means as said means is moved inward and at a different position of said means as said means is moved outward, a first lever with one cam step for actuating one of said operating means, a second lever having at least a pair of cam steps for operating the other of said operating means, an operator, said operator upon en-' gaging said single cam step effecting a movement of said first lever substantially equal to the movement imparted to said second lever by the operation of said operator upon both of said pair of cam steps, and means for moving said operator.

9. In an electrical control station, a pair of switches, rectilinear operating means effecting the switching operation, said switching operation occurring at one position of the rectilinear operating means as said means is moved inward and at a different position of said means as said means is moved outward, a first lever with one cam step for actuating one of said operating means, a second lever having at least a pair of cam steps for operating the other of said operating means, means rotatably mounting said levers in side-by-side relationship so that said one cam step is between said pair of cam steps, an operator, means including an operating handle for selectively positioning said operator along said levers, said operator upon engaging said single cam step effecting a movement of said first lever substantially equal to the movement imparted to said second lever by the operation of said operator upon both of said pair of cam steps.

10. In an electrical control station, a pair of switches, a first lever having a single cam step for operating one of said switches, a second lever having a pair of cam steps for operating the other of said switches, means rotatably mounting said levers, an operator, and means for pressing said operator against all said cam steps to effect rotation of said levers, said single cam step being approximately equal in height to the sum of the heights of said pair of cam steps.

11. In an electrical control station, a pair of switches, a first lever having a single cam step for operating one of said switches, a second lever having a pair of cam steps for operating the other of said switches, means rotatably mounting said levers, an operator, and means for pressing said operator against all said cam steps to effect rotation of said levers, said single cam step being approximately twice the height of either of said pair of cam steps.

12. In an electrical control station, a first lever having an arcuate surface with one cam step, a second lever having an arcuate surface with at least a pair of spaced cam steps, biasing means for said levers, means rotatably mounting said levers, circuit controlling mechanisms having actuators, means mounting said circuit controlling mechanisms near the free ends of said levers whereby said actuators are operated by movement of the free ends of said levers, and operating means including a member movable longitudinally along the surfaces of said levers having said cam steps, said member effecting rotation of said levers about said rotatable mounting against the operation of said biasing means to effect operation of said circuit controlling mechanisms.

CARL A. SCHAEF'ER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

